Mobile communication includes communication systems primarily using a voice signal. However, as techniques for mobile communication are being developed and demands therefore are being increased, mobile communication is being developed as a multimedia communication including not only voice, but also data, as well as moving images. In multimedia communication, an amount of data to be processed may be large, and a bandwidth of an allocated channel or a data transmission speed may be limited. Techniques for transmitting/receiving a large amount of data with limited data transmission speed by compressing, for example, moving picture expert group (MPEG) techniques, have been developed.
MPEG techniques for compressing multimedia signals may reduce a data amount of the MPEG frame consecutively changed as a function of time, and transmit the multimedia signal by using an intra-coded frame (I-Frame) decoded only by information of an image frame, a predictive-coded frame (P-Frame) including only motion vector values from the I-Frame, etc. Herein, even if the I-Frame and the P-Frame have few differences by the MPEG method or ocher application methods, they may have a transmission ratio of about 1:15 per second.
When a block error is generated at the I-Frame, a receiving side may receive the I-Frame again, so as to compensate the block error. When a block error is generated at the P-Frame, the receiving side may perform a motion estimation process and a motion compensation process for the previous frame and the next frame of the P-Frame, so as to compensate the block error. An apparatus for compensating the block error of an image frame according to an exemplary arrangement will be explained with reference to FIG. 1.
FIG. 1 is a block diagram showing the block error compensating apparatus of an image frame according to an example arrangement.
As shown, the block error compensating apparatus of an image frame may include a video codec decoder 10 for decoding an inputted image frame, compensating an error-generated image frame among the decoded image frame, and thereby outputting. The apparatus may include a memory 12 for storing an image frame processed in the video codec decoder 10. The apparatus may include a window interface 14 for converting the image frame inputted from the video codec decoder 10 into a corresponding format for displaying and thereby outputting. The apparatus may include a display window 16 for displaying the image frame inputted from the window interface 14.
A block error compensating method of an image frame according to an example arrangement will be explained with reference to FIG. 2.
FIG. 2 is a flow chart showing the block error compensating method of an image frame according to an example arrangement.
As shown, a method for compensating a block error of an image frame may include detecting an error-generated block in a decoded image frame (S20). The method may include judging whether a frame including the detected block is a P-Frame (S22). The method may include compensating the generated block error based on the previous frame and the next frame when the frame including the detected block is the P-Frame. The method may include displaying the frame where the bock error has been compensated (S26), which may be repeated. In determining whether a frame including the detected block is a P-Frame (S22), when a frame including the detected block is an I-Frame, the I-Frame may be received again (S23) and the block error-generated image frame may be compensated by the re-received I-Frame.
A method for compensating a block error of an image frame according to an exemplary arrangement will be explained in more detail.
The video codec decoder 10 may receive an image frame from a transmitting side thus to decode, then store the decoded image frame in the memory, and then detect an error-generated block the decoded image frame (S20). Herein, the image frame may be composed of blocks having predetermined regions.
When an error-generated block is not detected in the decoded image frame, the video codec decoder 10 may output the image frame to the window interface 14. When an error-generated block is detected in the decoded image frame, the video codec decoder 10 may judge whether an image frame including the error-generated block is a P-Frame (S22).
When the image frame including the error-generated block is not the P-Frame but an I-Frame, the video codec decoder 10 may receive the I-Frame again (S23) and the block error-generated image frame may be compensated by the re-received I-Frame thereby to be outputted to the window interface 14.
On the other hand, when the image frame including the error-generated block is the P-Frame, the video codec decoder 10 may perform a motion estimation process and a motion compensation process for the previous frame and the next frame thereby to output the image frame in which the block error has been compensated to the window interface 14 (S24).
The window interface 14 may convert the inputted image frame into a corresponding format to be suitable for the display window 16, and output the converted image frame. The display window 16 may display the inputted converted image frame (S26).
As described above, in the block error compensating apparatus of an image frame, a block error-generated frame may be received again, or a motion estimation process and a motion compensation process for the previous frame and the next frame may be performed, thereby compensating the block error-generated frame.
However, in the block error compensating apparatus of an image frame, since a block error-generated frame may have to be received again, or the motion estimation process and the motion compensation process for the previous frame and the next frame may have to be performed, an additional memory for operating a large amount of data may be necessary and data may not be processed in real-time.